To celebrate the 100th installment of its highly popularized Digital Short series, Saturday Night Live last night unleashed a star-studded 100th episode that featured Justin Bieber, Usher, Lonely Island and Justin Timberlake. The comical video followed a look back at the antics throughout the previous shorts, making note of appearances by Justin Timberlake, Lady Gaga, Natalie Portman and Jon Hamm. Before closing things out in typical SNL fashion, Will Ferrell made an appearance to throw in his two cents about his impressive track record as an SNL alumni.